Giant magnetoresistive (GMR) sensors used as read elements in magnetic data storage and retrieval systems need to operate in a linear and stable fashion. Especially when used as read elements in a multi-track read/write head in magnetic tape data storage and retrieval systems, GMR sensors also need to operate as close to equivalent to each other as possible.
GMR sensors, however, are unfortunately prone to defects which can cause instability and bias point changes during their operation in such data storage and retrieval systems. As a result, there exists a need for a GMR sensor that overcomes such problems. Such a GMR sensor would minimize the effects of such defects, thereby improving manufacturing yield and allowing the sensor to operate in a more stable fashion when used in data storage and retrieval systems.
More specifically, such a sensor would be built incorporating topographic features that provide equivalent magnetic fields large enough to minimize the effect of random manufacturing variations, thereby providing greater sensor equivalency in multi-track read/write heads. Such topographical features would comprise a step in a layer beneath the working surface of the GMR sensor. Such a step would be parallel to the working surface of the GMR sensor, such as the tape bearing surface of a GMR sensor in a magnetic tape data storage and retrieval system. Such a feature would provide for a GMR sensor which allows multi-track GMR heads to be built with better yield, better performance, and less sensor variation between tracks.